Snow grader

ABSTRACT

This invention relates to a snow grader comprising a support frame, a plurality of baffle means attached to said frame with the bottom thereof being in substantially the same plane as the bottom of said frame, runners movably mounted on said frame, and means for moving said runners to and from a position above the bottom of said frame to a position therebelow, said baffles being substantially parallel to each other and positioned at 90* to the direction of travel of the grader.

United States. Patent 1191 Brown June 11, 1974 [5 SNOW GRADER 2,710,4656/1955 Timerson ..37/123x 1761 Invemon Newtonw-BmwmHydeParhvt- 5133122231325 32937131131111:

05665 3,576,214 4/1971 Ratcliffe 172/393 [22] Filed: Oct. 1,1971

Appl. No.: 185,750

Primary Examiner-Robert E. Pulfrey Assistant Examiner-Eugene H. Eickholt52 i? 48:14am ir '.,.E9 nl 9e ";s @aq [52] US. Cl 172/789, 172/393,37/50 [51] Int. Cl. E023 3/12 [57] ABSTRACT [58] Field of Search172/787, 786, 789, 396, This invention relates to a snow grade-r Com 1 vprlsmg 21 3775042 122423 support frame, a plurality of, baffle meansattached to said frame with the bottom thereof being in substan- [56]References C'ted tially the same plane as the bottom of said frame, run-UNITED STATES PATENTS I ners movably mounted on said frame, and meansfor 438,829 10/1890 Rose et al. 37/52 moving ai runners to and from aposition above the 625,589 5/1899 Mulder 37/123 bottom of said frame toa position therebelow, said 768,170 8/1904 Dorsett 172/393 X bafflesbeing substantially parallel to each other and 1258,7 49 3/1918Culbertson 172/393 positioned at 90 to the direction of travel of thel,428,973 9/1922 Northon 172/387 x graden 1,718,094 6/1929 Van Patten 137/50 1 2 l04,675 1/1938 Ruff 172/393 X 1 Claim, 3 Drawing Figures /|O I[26 1 3o 27 25 3 w M 24 '3 12+ (18 T Q o h 29 32 ,J /"Qe I! 1 '1 L. L 1j PATENTEIJJUM v 1 I974 I'N'VENTOR f In N R] 6 BY Mm;

NEWTON W. BROWN 2 ATTORNEYS snow GRADER BACKGROUND OF THE INVENTION Aswinter sports have become more popular and diversified, the areassuitable for engaging in such sports have become more crowded and morelimited. This is particularly true with respect to the sport ofsnowmobiling. In some areas, legislation has further limited areas whichcan be used forthis sport, and with large numbers of people engaged inthis sport, a serious problem has arisen with respect to maintenance ofsnowmobile trails and roads. Specifically, snowmobiles usually rely ontreads to propel them across the snow. Such treads dig into the snow,leaving a rough, corrugated surface which becomes even more irregularupon repeated use of the trail. Freezing and thawing cycles and repeatedsnowfall act to aggravate this irregularity to the point where sometrails and roads become unusable. Attempts to maintain the trails havenot been successful because equipment presently in use is not suitablefor smoothing the trails and packing them so that they can be used bysnowmobiles. The surface on which snowmobiles travel must not only besmooth but also packed to some extent in order to permit proper functionof the means, such as tread, which act to propel the snowmobile.

BRIEF SUMMARY OF THE INVENTION The present invention relates to gradingapparatus which will quickly and conveniently smooth and pack areas ofsnow so that they will be suitable for use by snowmobiles.

Briefly stated, the present invention comprises a snow grader comprisinga support frame, a plurality of baffle means attached to said frame withthe bottom thereof being in substantially the same plane as the bottomof said frame, runners movably mounted on said frame, and means formoving said runners to and from a position above the bottom of saidframe to a position therebelow, said baffles being substantiallyparallel to each other and positioned at 90 to the direction of travelof the grader.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of agrader according to the present invention;

FIG. 2 is a top plan view thereof; and

FIG. 3 is an enlarged partial view of the lifting and locking deviceillustrated in FIG. 2.

DETAILED DESCRIPTION Referring to the drawings, and in particular FIGS.-1 and 2, there is shown a grader 10, which comprises a support frame 11,preferably formed of angle iron, and a plurality of snow leveling means12, attached to the frame as by welding, which are suitably solidbaffles formed of iron or other rigid material which are furtherstrengthened against dislocation by means of struts 13. While threebaffles have; been shown, it will be evident that more'c'an be used ifdesired.

A drawbar I4 is attached to a shaft which is in turn rotatably mountedto the frame by means of standard bearing assemblies 16. The drawbar hasa swivel hitch 17 which rotates freely through 360 attached to itsforward end and it is by this means that the grader is connected to thevehicle which is to draw it through the snow. The drawbar also hasaffixed to it a plate 18 having an arcuate upper surface 19 and alocking detent 20 whose purpose will be explained later in connectionwith FIG. 3. The drawbar 14 is mounted near the center of the length ofthe grader frame 11 so as to minimize the influence of the up and downmotion of the vehicle drawing the grader and thereby permit the graderto float freely over the surface being graded.

Runners 21 are attached to shaft 23 by means of legs 22. The runners arepreferably ski-shaped in form in order to permit the grader to ride oversnowy surfaces and are used as a means of moving the grader to variouslocations when it is not in use. The shaft 23 is mounted on the frame 11by means of standard bearing assemblies'24 so that it can be rotated,thereby moving the runners 21 to a position above the bottom of theframe, or to the position therebelow as illustrated in FIG. 2.Restraining means, such as a chain 28, are used to insure that therunners 21 will not be rotated beyond the position desired. Rotation isaccomplished by means of lifting and locking means comprising the arm 25affixed to the shaft 23, which arm 25 is connected to a rod 26, which isin turn attached to an L-shaped arm 30 which is movably attached to theplate 18 by means of a pivot pin 32. This L-shaped arm 30 has movablyaffixed thereto-a dog 33, with a locking snout 34 and a bottom surfaceshaped to travel along the arcuate surface 19 of the plate 18 as bestshown in' FIG. 3. Locking bolt 37 passing through slot 38 is used tomovably mount the dog 33 to the arm 30. Pivoting the L-shaped arm 30 bypulling on the rope 27 causes the dog 33 to ride along the arcuatesurface 19 to a position where it will be locked into the lockingdetent20 of the plate 18. This acts to maintain the runners 21 in theirextended position below the frame. The dog 33 is counterweighted at itsforward end 36 so that when the L-shaped arm is further pivoted it willunlock from the detent 20 and move along the arcuate surface 19, therebycausing the runners 21 to be lifted above the bottom of the frame 111.The means for moving the L-shaped arm 30 about the pivot pin 32 to raiseor lower the runners 21 is a rope 27 which is manipulated by theoperator of the vehicle pulling the grader. Keeper chain 35, attached tothe frame and passingthrough slot 31 in L-shaped arm 30, can be used toadjust the height to which the runner can be raised. Also provided ischain 29 attached to the frame 11 and to the drawbar 14 for adjustingthe height of the grader with respect to the drawbar 14. It may bedesired to vary the height of the forward end of the grader, dependingupon snow conditions and conditions of the surface upon which the graderis acting.

While operation of the device is largely evident from the foregoingdescription, it will be seen that once the grader is attached to thedrawing vehicle by means of a swivel hitch 17 the grader can be towed tothe area where it is to be used in an inoperative position by lockingthe runners 21 into their position below the frame. Once the area isreached which is to be graded, the runners 21 are retracted by theoperator pulling the rope 17, thereby causing the L-shaped arm 30 topivot to release the dog 33 and permit rod 26, arm 25 and legs 22 tomove the runners. The correlated movement of the arm 30, dog33 and rod26 is. further illustrated by the broken line representation of theseelements which shows the position of these elements (30, 33', and 26)when the dog has been released from its locked position in detent 20.The frame 11 then rests on the surface to be graded together with thebaffles 12, and their combined weight as the grader is moved causes thesnow surface to be treated so as to scrape the high spots and depositthe snow onto the low spots while also packing the snow. This lifting ofthe snow by the baffles also acts to deaerate snow and the sliding ofthe grader also packs the deaerated snow leaving to the rear of thegrader a substantially even, smooth, hardened trail.

As to materials, the support frame, baffles, drawbar assembly andlifting and locking means are preferably made of metal, such as steel oriron, since it provides the best resistance to wear and the weightnecessary to give the most effective scraping, packing and smoothmg.

It will be understood that it is intended to cover all l. A snow gradercomprising a horizontal support frame, a plurality of substantiallyvertical baffles attached to said frame with the bottom thereof being insubstantially the same plane as the bottom of said frame, ski-shapedrunners movably mounted to said frame at the rear portion thereof, meansaffixed to said runners for moving said runners to and from a positionabove the bottom of said frame to a position therebelow and said frameand baffles into and out of contact with the surface of the snow, meanson said moving means to lock said runners in the position below thebottom of said frame, means for attaching said grader to a vehicle, andmeans on the forward portion of said frame to vary the height of theforward end of the grader in relation to said attaching means, saidattaching means extending from a point substantially about the middle ofthe length of said frame to a point in front of said frame and saidbaffles being substantially parallel to each other and positioned at tothe direction of travel of the grader.

1. A snow grader comprising a horizontal support frame, a plurality ofsubstantially vertical baffles attached to said frame with the bottomthereof being in substantially the same plane as the bottom of saidframe, ski-shaped runners movably mounted to said frame at the rearportion thereof, means affixed to said runners for moving said runnersto and from a position above the bottom of said frame to a positiontherebelow and said frame and baffles into and out of contact with thesurface of the snow, means on said moving means to lock said runners inthe position below the bottom of said frame, means for attaching saidgrader to a vehicle, and means on the forward portion of said frame tovary the height of the forward end of the grader in relation to saidattaching means, said attaching means extending from a pointsubstantially about the middle of the length of said frame to a point infront of said frame and said baffles being substantially parallel toeach other and positioned at 90* to the direction of travel of thegrader.